In European antiquity, philosophers largely wrote in Greek. Even after the Roman conquest of the Mediterranean and the demise of paganism, philosophy was strongly associated with Hellenic culture. The leading thinkers of the Roman world, such as Cicero and Seneca, were steeped in Greek literature; Cicero even went to Athens to pay homage to the home of his philosophical heroes. Tellingly, the emperor Marcus Aurelius went so far as to write his Meditations in Greek. Cicero, and later Boethius, did attempt to initiate a philosophical tradition in Latin. But during the early Middle Ages, most of Greek thought was accessible in Latin only partially and indirectly.
Elsewhere, the situation was better. In the eastern part of the Roman Empire, the Greek-speaking Byzantines could continue to read Plato and Aristotle in the original. And philosophers in the Islamic world enjoyed an extraordinary degree of access to the Hellenic intellectual heritage. In 10th-century Baghdad, readers of Arabic had about the same degree of access to Aristotle that readers of English do today.
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